Spin fluctuations in quantum dots
arXiv:1408.5662 · doi:10.1103/PhysRevB.90.195308
Abstract
We explore the static longitudinal and dynamic transverse spin susceptibilities in quantum dots and nanoparticles within the framework of the Hamiltonian that extends the universal Hamiltonian to the case of uniaxial anisotropic exchange. For the limiting cases of Ising and Heisenberg exchange interactions we ascertain how fluctuations of single-particle levels affect the Stoner instability in quantum dots. We reduce the problem to the statistics of extrema of a certain Gaussian process. We prove that, in spite possible strong randomness of the single-particle levels, the spin susceptibility and all its moments diverge simultaneously at the point which is determined by the standard criterion of the Stoner instability involving the mean level spacing only.
23 pages, 8 figures
References in corpus (13)
- Spintronic magnetic anisotropy
- Many-Body Physics and Quantum Chaos
- Spin-orbit interaction in quantum dots in the presence of exchange correlations
- Tunnelling density of states at Coulomb blockade peaks
- The Interplay of Spin and Charge Channels in Zero Dimensional Systems
- Mesoscopic competition of superconductivity and ferromagnetism: conductance peak statistics in metallic grains
- Thermodynamics of ultrasmall metallic grains in the presence of pairing and exchange correlations: Mesoscopic fluctuations
- Anisotropy in Ferromagnetic Nanoparticles: Level-to-Level Fluctuations of a Collective Effect
- A quantum dot close to Stoner instability: the role of Berry's Phase
- A Universal Interacting Crossover Regime in Two-Dimensional Quantum Dots
- Mesoscopic bound on anisotropy in itinerant ferromagnets
- Statistics of Spin Fluctuations in Quantum Dots with Ising Exchange
- The coexistence of superconductivity and ferromagnetism in nano-scale metallic grains
Cited by in corpus (5)
- Mesoscopic Stoner instability in open quantum dots: suppression of Coleman-Weinberg mechanism by electron tunneling
- Inelastic electron scattering off a quantum dot in the cotunneling regime: the signature of mesoscopic Stoner instability
- U(1) and SU(2) quantum dissipative systems: The Caldeira-Leggett vs. the Amegaokar-Eckern-Schön approaches
- Tunneling density of states in quantum dots with anisotropic exchange
- Stoner-type theory of Magnetism in Silicon MOSFETs